Apparatus for purifying burner-gases.



J. B. F. HERRESEQR MMRATUS FOR PURIFYING BURNER GASES.

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ATTORNEYS teureren. sraarnsmirarnur onirica.

JOHN B. FQHERRLESHOFF, or' NEW YORK N. Y.,

- yCOMPANY, Aor NEW YORK.' N. Y., a loonieonnyrron or NEW Yoan.

APPARATUS FR PURIF'YING BURNER-GASES.

Specification of Letters Patent.

riginal application filed` February 10, 1906, Serial No. 300,364. Divided and this application file-d. April To all whom 'it may concern:

Be it Known that I, JOHN BROWN FRANCIS Hnnnnsuorr, a citizen'of the United States,

andr resident of the borough of. Manliattan,

city, county.1 and State ofNeW York, have invented certain new and useful improve-- ments in Apparatus for Purifying Burner- Gases7 o which the foliowiugfis a specifi-A cation.

My invention relates to apparatus for they purification of burner gz'ses such asl are produced from sulid ores and other materialsI used in the manufacture .of sulfuric acid, and 'especially for effecting a purification which Will render such gases suitable for the nninufarture oi sulfuric anhydrid and of sulfuric acid bythe so-calledV contactprocess in which the sulfur `dioXid contained in such gases caused to combine with' oxygen -by the catalytic action of platinunror equivalent material.

rlie'continued efiicency of the'contact processl for the manufacture of sulfuric 'anhydrid depends among other things upon the proper purification of the burner gases before they are allowed to' enter thecontact chamber. .it has been found that the purication vpreceding the catalytic process should be soconducted as to remove certain detrimental impurities amongl which I will 'naine particuarlysulfuric acid (present in the form oi mist) sulfur, arsenic,antimony,

selenium, tellurium and hydrofiuoric acid. The failure to eliminate these bodies before the catalytic reaction occurs will materially reduce the eficiency of the contact process, such bodies acting, as it were, as a poison by diminishing' or destroyingr the catalytic activity of the platinum. (in the other hand, nitrogen, which is a substitutie of the bui-nei` gas mixture and which does not enter into the reaction, .may be carried along with the parified Wit-hout any detrimental eif'ect on the contactprocess.

Reference is to be had to the acconuianying drawing, which is a diagrammatic if'iew,

partly in section', ot' an apparatus embody'- ing my invention.

A designates furnaces Where the ore is roasted. The furnace gases or burner pass through conduits B into a dust .chainber C Ot a cross section considerably greater than that of the 'conduits B, so that the `gases Will move more slowly in the dust chamber dangerous to the catalytic'acirity ofi y'liaiuuim and must be removed before 1.'

the contact inassto a very' niatewl f 1907. Serial No. 366,514.-

iratenra Nrw. ie," roos.

ASSIGNOR-TO GENERAL CHEMICAL i C, allowing the suspendedI solid particles' .to 55 temperatureis reduced to'abotit 65W F. at'

VThe gasesl their entrance. into-the tower. pass upward in the to ver. E which contains a filling .F of quartz stones or other suitablematerial, and a large quantity oi' a purify 111g liquid, preferably cool weak sulfuric 6A acid (for instance of B.) trickles don/'n.-

ward overthe filling. This treatment ivithf iinely divided cool Weak sulfuric acidlias a double effect, one of Which is to furtherccol the gases, and the other to scrub thema. The, 7 0

chief constituent'soif the burner gases are f Y SC2, O, and N. Thefg'ases also'contaiu ya -rious liquid and solid impurities, and the settling and scrubbing system has to'be 'so` designed that it Will ehminate Witlrpractical completeness all of the solid impurities.|`- The sulfur, like solid (sublimed) arsem` has a yerv detrimental influence on the auf..

tivity orf the contact substance.

The Liiquid impurities such dissoived arsenic koccur in the sulfuric acid, which is always formed when which in the. gases is present in 'the nature, of .a mist, vand it has been found that if auch. sulfuric acid is carried along,` through i remainder of the purifying process it roasting` sulids and ously interferes Awith. the eficioncj: said process, requiring a .fery thorough and morelengthy purification than necessary ot Wise. Furthermore the nresence oit .sultu l A 'a acid in the Contact chambers interi@ the efficiency of the catalytic action.. arsenic. (as-well as Hifi und Sei is o gases enter the Contactchamber, or such` arsenic will soon diminish the activif The preliminary cooling i' the g, on. their way to the cooling and scrubbing tower E is of assistance., as it. enables the gases to be purified more readily when they come in contact with the Weak 'acid t' 'iclrling down in said tower: in the scri` i. tower'the purification. the burner gases from S, il, 550 its, and other detrimental impuri-- ties is carried on very efficiently owing to the large surface and to the intimate conheads for su cated at H, H2, and t-he outlets for the eratedv in the scrubbing towers and 4the gases may be passed in succession through several scrubbin towers.. Thus,

the drawing shows two ad itional scrubbing towers E', P12-with: fillings F', of me same character as hereinbefore described.

.Pipes G, Gr' connect the upper portion of one tower with the; lower portio n""of the next and serve to convey the gases.""'1-`he spray lylng the weak acid are indiweak acid at J, 'JQ-"52.111 refer to use the same body of acid over an over again, and for this purpose, the 'acid from the outlet'J passes into a cooler K" and thenthrough a settling box L having batheboards or other means vfor'causin impurities 'tojoe thrown down.l A pura'ip returnsthe cooled and purifiedA acld through a piI'eN to the spr?7 head H. The acid from the towers E', 2 is preferabl ledtto thel same .cooler K', then to the settlmgvbox L', and finally brought back to the spray beads H', H2., through the pipe N',by the pump M. The cooling of the acid is required because it becomes heated in the scrubbing towers, and on thefother,

hand the acid should becool to erform its work efficiently. Some S02 is of) course absorbed by the' weak acid, bu the acid' soon becomes saturatedwith that mount of SO2, which it can absorb at the temperature to which it is heated in, the scrubbing towers.

The cool acid does indeed absorb an`additional amount of S02', but as the acid oe-A comes heated, this additional amount is libasses along with the gases; The towers E, E2, as wellas the coolers K, K', and scttling boxes L, L', should be closed to the atmosphere so as to prevent the escape of any SO2 which may be liberated in any onel of these apparatus. y I

The purification in the scrubbing towers should be so thorough that the solid impurities will be practically eliminated and will not perceptibly affect the operation of the remainder of the apparatus. The gases thus deprived of the solid impurities of a portion of the liquid mist, andof gaseous impurities aswell, pass through the conduit G2 to the filter C, preferably filled with fine, dry sand coke or other medium, therefore it is very important that nd solid matter should be permitted to enter the filter. The filter is of great area and depth. ln this filter, the acid mist containing As, and most of the moisture, lare removed from the gases and the puriiicationis completed. ll"inally,' the gases are dried-in 'a drying tower I by contact with concentrated sulfuric acid trickling down in the usual way. A blower Q, or-

other suitable device is employed for causing the gases to follow the path set forth. The

vpurified gases pass onto the contact chamb er or other apparatus.`

'Phe treatment hereinbefore described removes the HZSOM S, HFl, As, and other` detrimental impurities from the burner gases but leaves the contents 'of S02 and of, other constituents, that is, chiefly C and N, practically unaltered. Those constituents therefore, SO2 and 0, which are the active Aconstituents in the. contact process and N which is inert, are preserved in. their practical entirety, while the detrimental impurities are removed.

The gases, at the end of the purifying treatment herein described, should satisfy an optical test showing their practically absolute freedom from solid or liquid matter.

' The present application is a division of an application filed yby me in the United States Patent Oiice on February 10, 1906,

Serial No. 300,364, in which the process herein described is claimed.

I claim:

1. The herein described gas purifying apparatus, `comprising a scrubbing tower having a spray inlet at the top and a liquid out- Vlet at the bottom and also aninlet and an outletjor the gases, a cooler for receiving the liquid from the outlet of the scrubbing towelg a purifying or' settling chamber connected with the outlet'of said cooler, means for. circulating the spray liquid through the scrubbing tower, the cooler and the settler,

and apparatus connected with the gas outlet of the scrubbing tower for further treatl ing the gases.

2. The herein described fraspurifving apparatus, comprising a scrubbing tower having a liquid inlet at the top, a liquid outlet at the bottom, a gas inlet at the bottom, and- 'a gas outlet at the top, a cooler connected with the liquid outlet of the scrubbing tower,

a settling chamber connected with the out,- let of the cooler, means of conveying the liquid from the settling chamber to the liquid inlet/'of the scrubbing tower, tlie said scrubbing tower, as well as thefcooler and the settling chamber, being closed to the atmosphere, and apparatus connected ,with the gas outlet of the scrubbing tower, for further treating the gases.

ln testimony whereof, I my name, in the presence of two subscribing witnesses.

JOHN c. F. HERmasHorr. Witnesses:

.loi-1N Lorna,

JOHN A. KmiLeNrm.

have hereunto set p 

